Burgundy casually mentioned that the brakes didn't feel right on the Yukon XL (2005) the other day. She said it seemed like it took more effort to stop it. I looked it over last night but haven't had time to get into any detail on diagnosis, but I noticed it has a hydraulic booster instead of vacuum. I've noticed before when turning at idle the power steering seems a bit week so I'm assuming the booster would be week too. Is there any testing I can do on it or just throw a pump at it and hope it fixes it?